Say it with love ... and DNA! Researchers from Harvard Medical School
have made letters and wingdings out of DNA. Each one of the letter above
is made from a single strand of the genetic material:

Each strand is unique, and folds to form a rectangular tile. When
mixed, neighbouring tiles stick to each other in a brick-wall pattern,
and shorter boundary tiles lock the edges in place.

In their simplest configuration, the tiles produce a solid 64-by-103-nanometre
rectangle, but Wei and his team can create more complex shapes by leaving
out specific tiles. Using this strategy, they created 107 two-dimensional
shapes, including letters, numbers, Chinese characters, geometric shapes
and symbols. They also produced tubes and rectangles of different sizes,
including one consisting of more than 1,000 tiles.